The major objective of the University of Alabama (DAB) Center for AIDS Research (CFAR) Flow Cytometry Core is to provide state-of-the-art flow cytometry services to support AIDS research programs. Flow cytometry is a unique and powerful technology for analyzing the fluorescent properties of particles and can be readily applied to determining the phenotype and function of cells, as well as utilized for isolating defined cell populations by sorting. In recent years the use of flow cytometric analyses in HIV research has become ever more prominent as newer approaches for dissecting the interactions between HIV and cells of the immune system have been developed; fluorescent based reporter systems have been harnessed to monitor virus replication, reactivation, and recombination; and sophisticated technological advances in instrumentation have provided new platforms for high-speed polychromatic analyses and cell sorting. The CFAR flow cytometry core is, therefore, a vital and versatile resource for promoting and facilitating AIDS research. The flow cytometry core's mission is to maximize the benefits of this technology by providing the necessary instrumentation within a well organized, centralized, facility that is capable of handling potentially infectious material. It provides training opportunities and consultations, and it also serves as a conduit for fostering interactions between investigators and laboratory personnel with diverse interests and expertise. During the previous funding period the CFAR flow cytometry core has undergone a significant equipment upgrade, with the installation of a BDFACSAria cell sorter as well as a BD-LSR-II analytical flow cytometer. The flow cytometry core has also improved its visibility and accessibility as well as enhanced education and training initiatives. As a result of these endeavors the usage of the flow cytometry core has increased more than three-fold since 2002. The flow cytometry core has supported the research activities of 184 different individuals from 69 Principle Investigators laboratories and has contributed to basic, clinical, and translational initiatives in the areas of viral pathogenesis, anti-viral research, cellular immunity, and vaccine design. The core has supported the activities of 88 NIH grants and contributed to 172 publications The aims of the flow cytometry core are to now build upon our progress-to-date by further enhancing services, and education and training activities so that users are empowered to take full advantage of the sophisticated instrumentation that is available. These efforts include, based on a needs assessment analysis, the installation of a third flow cytometer and a BioPlex flow cytometer for multiplexed analysis of biomolecules (e.g. cytokines) in the beginning of 2008. We also aim to promote innovation by working with users, and fostering collaborations and crosscore partnerships that encourage cutting-edge AIDS related research activities.